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Discussion Starter · #1 ·
I hear this a lot?
what is actually involved?
Costs? Can it even be done to a 380sl that has a "single timing chain"?
Please advise.
 

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1980 450SL & 1988 560SL
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It all about a single row 380. Single is bad double is good. People convert the 380's to the double chain to stop the failure prone to the single row chains. All the gears on the front of the engine have to be changed to match the new chain. Cost, not sure.
 

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For model year 1981, Mercedes substituted a lighter, more efficient all-alloy 3.8 liter V-8 for the old reliable iron-block 4.5-liter V-8. And along with it came trouble.

The engine has a single-row timing chain, which as the miles piles on, tend to stretch. Unchecked, the chain can jump its sprockets, causing pistons to collide with valves, leaving the 380SL owner facing a $6,000 repair bill. During 1984, Mercedes switched to a double-row chain and solved the problem.

Though it was not an announced recall, Rugg says that at one time Mercedes did convert some of the early 380SLs, free of charge, to double row chain for some customers. "The only way to know if a car is converted is to take off the valve cover and look."

Converting one now is a $2500-$3000 proposition, said Marx. But Marx added that the conversion is unnecessary if the owner changes the chain and tensioner every 40,000 miles -- a $300 job.



Mercedes Benz 107 SL SLC Resource Center 280 280sl 350 350sl 380 380sl 420 420sl 450 450sl 500 500sl 560 560sl


Keep in mind this article and its prices are a bit outdated......
 

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Also keep in mind that the single row chain issue was for North American production vehicles. Euro versions of the 3.8L M116 had the double row from the beginning.
 

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2008 E320 Bluetec, 1988 560SL totalled unto death). 1997 Dodge Ram 1500, 1983 300CD
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single row 380SL

1981 - 1983 had single row chain, 1984 and 1985 had the dual row. There is nothing wrong with a well maintained single row setup. You may want to start thinking about changing the chain at about 60k instead of 90k miles as with the dual chain. Keep an eye on the stretch.

There are conversion kits but I don't recall the cost. I would budget about $3000 if you must do it.
 

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82 380SL 96 SL500 03 SL500
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I looked at the shop's flat rate software package after I bought my 380sl (unknowing newbie). Best recollection is shop time of 4hr to change timing chain & 44hrs to change over to double row chain. So, multiply hours times your shops rate $$$$$ and then include parts.

Those figures inspired the decision that I would just replace the single row chain if that was what was there.

Happily, using a bore scope through the oil filler hole a double row chain could be seen.

Alan
 

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Alfa Romeo 1750 GTV, BMW 2002, BMW 528it, R107 380SL, S202 C43T.
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Also keep in mind that the single row chain issue was for North American production vehicles. Euro versions of the 3.8L M116 had the double row from the beginning.
So the engine in the 380SL that I just bought (116.962) has a dual row chain? Its an Australian delivered car, but I believe these to have Euro-spec engines...

Thanks in advance on this one!
 

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Forum Administrator , RC Colas® & Moon Pies®
1981 380SL 151K: 2005 S500 116K
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If you really want to be sure, you can take a flashlight and a small mirror, like a dental mirror, and angle it into the oil filler neck on the valve cover. With paitience and a bit of wiggling, you CAN see the chain and determine if it is a single row or double.

Don't despair if it's a single. The car has lasted over 25 years with it so plan on changing it every 40k or so. If your car is not a daily driver, you might not have to change it for another decade.
 

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1978 280slc
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My mechanic said the best thing for the timing chain system if changing the motor oil. I thought about it when I did the pickup a 22re but it cost like 500$ for a very common engine, too damned expensive thought the pickups lasted 185K.
 

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1982 SL 380, 2001 325i, 2003 Toyota Highlander
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I looked into this in April. The conversion was going to be 4K minimum. I found an indie who changed the single row at 60k miles for $900. Interestingly, he wasn't really fond of the dual chain either - said it was more of a design flaw than a reliability question. Since this car will see about 2K/year, it really wasn't worth it for me.
 

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1989 560SL
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If you really want to be sure, you can take a flashlight and a small mirror, like a dental mirror, and angle it into the oil filler neck on the valve cover. With paitience and a bit of wiggling, you CAN see the chain and determine if it is a single row or double.

Don't despair if it's a single. The car has lasted over 25 years with it so plan on changing it every 40k or so. If your car is not a daily driver, you might not have to change it for another decade.

OLD POST---I agree 100%! Forget changing it every 40k miles---do it at 20k intervals which will probably be 10yrs of driving!!
 

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Forum Administrator , RC Colas® & Moon Pies®
1981 380SL 151K: 2005 S500 116K
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OLD POST---I agree 100%! Forget changing it every 40k miles---do it at 20k intervals which will probably be 10yrs of driving!!
Alternatively, you can knock a hole in the valve cover to get the best possible view for conversion confirmation.
 

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1980 450 SL
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For model year 1981, Mercedes substituted a lighter, more efficient all-alloy 3.8 liter V-8 for the old reliable iron-block 4.5-liter V-8. And along with it came trouble.

The engine has a single-row timing chain, which as the miles piles on, tend to stretch. Unchecked, the chain can jump its sprockets, causing pistons to collide with valves, leaving the 380SL owner facing a $6,000 repair bill. During 1984, Mercedes switched to a double-row chain and solved the problem.

Though it was not an announced recall, Rugg says that at one time Mercedes did convert some of the early 380SLs, free of charge, to double row chain for some customers. "The only way to know if a car is converted is to take off the valve cover and look."

Converting one now is a $2500-$3000 proposition, said Marx. But Marx added that the conversion is unnecessary if the owner changes the chain and tensioner every 40,000 miles -- a $300 job.



Mercedes Benz 107 SL SLC Resource Center 280 280sl 350 350sl 380 380sl 420 420sl 450 450sl 500 500sl 560 560sl


Keep in mind this article and its prices are a bit outdated......
I've got an '80 450sl with 62,000 miles. Don't know if PO ever had any chain work done. Does this mean I don't have to worry about it or should I have my mech replace guides and chain?
 

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1987 560SL
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I've got an '80 450sl with 62,000 miles. Don't know if PO ever had any chain work done. Does this mean I don't have to worry about it or should I have my mech replace guides and chain?
It's not the miles it is the years. The guides get brittle with age (and heat). One option is to pull one valve cover (four screws, the valve cover gasket is re-useable) and just look at the guides, if they are light color and new looking congratulations. Dark brown, cracks, wear from chain, etc. replace them now. May as well do new chain, cam sprockets, upper guides, chain tensioner, and plastic oilers all at once. No need to remove engine or fool with the lower guides or lower sprockets. On the 1980 the right cover is easier to remove than the left due to the routing of hoses. If you have a video inspection camera you might be able to bypass the valve cover removal, but IMHO it is better to open and inspect rather than video and guess.
 

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'79 450 SL.. '13 Escape SE 2.0 Turbo...'06 Hummer H3....'84 Ford F-150 HO..'62 TBird Convertible..
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I heard a funny noise on my '79 a couple years ago..83K miles..The top guide had broken..Went ahead with new chain when we changed the guides..
 

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1987 560SL
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Thanks for the info. Will pull that cover sometime this week and check it out.
Old rail color left, new rail color right. Many advocate using original MB parts. Search this board you will see much darker examples. Old sprocket left, hard to see wear in pic easier to see if superimposed. These SWAG sprockets were $20 each well worth the effort.
 

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